[A novel immobilized trypsin on hydrophilic polymer modified Silica beads for proteome characterization]

A new type of immobilized trypsin was prepared using hydrophilic polymer modified silica microparticles (HPMSM) synthesized by atom transfer radical polymerization (ATRP) as the substrate material. ATRP modification led to densely packed hydrophilic polymer chains grafted on the microparticles surface which resulted in largely increased trypsin loading amount and minimized the nonspecific adsorption of proteins and peptides. Therefore, ultra-fast and highly efficient protein digestion was achieved with minimized sample loss. For standard protein bovine serum albumin (BSA), 1 min digestion led to the identification of 93 peptides, which covered 91% amino acid sequence of the protein. This immobilized trypsin was further successfully applied to the digestion of complex protein samples from yeast and 666 proteins were identified after 3 min digestion, which exceeded the number of identified proteins after 12 h solution digestion.